LORIUM. – An ancient diocese established on an imperial villa at the 12th mile on the Via Aurelia, later renamed Castel di Guido. Within its territory, a basilica was also built over the tomb of the holy martyrs Rufina and Seconda by Julius I, which was renovated by Hadrian I (Lib. Pont., I, p. 508) and enriched by Leo IV (ibid., II, p. 122), but was later destroyed by Saracen incursions in 847 and 876.
Near this site, which Sergius III restored in 906 and which Bishop Peter fortified with walls and a moat under Benedict IX, the suburbicarian bishops of L. established their see. The first historically certain bishop is Petrus Lorensis, who took part in the Synod of 487, although local Christian traditions may date back to the 4th or even 3rd century (Nuovo bull. d'arch. crist., 17 [1911], p. 109). In 501, the bishop of L., from the place of martyrdom of the aforementioned saints, styled himself “episcopus ecclesiae Silvae Candidae” and also “episcopus S. Rufinae.” In November 1037, Benedict IX appointed the bishops of Selva Candida as chancellors of S. Romana Chiesa, among whom Cardinals Umberto and Mainardo distinguished themselves. Due to depopulation, in 1120 Callixtus II united the diocese of PORTA (v.).
In 1226, Gregory IX deposed the last Benedictine abbot. Through the influence of Frederick II, Archbishop Siegfried II of Mainz obtained in 1229 the submission of the abbey and the exile of the Benedictines, who were replaced by Cistercians. However, in 1248 Siegfried III, with the consent of Pope Innocent IV, replaced even these with Premonstratensians, summoned from the abbey of Allerheiligen (All Saints) in Baden. Following disputes between the bishopric of Mainz and the Palatinate, Lorsch was pledged in 1461 to the Count Palatine; in 1555, after the Peace of Augsburg, this prince—of Lutheran faith—drove out the Premonstratensians as well and installed as provost a married monk, Johannes Carpentarius. In 1563, the convent was transformed into a religious house for Protestants. The Thirty Years’ War brought severe damage to the conventual buildings of Lorsch: in 1621 Spanish troops besieged and burned them, and when Lorsch returned to the control of the Archbishop of Mainz in 1623, it was no longer capable of recovery, nor did the Premonstratensians succeed in returning despite repeated attempts. In 1803, the territory of Lorsch was incorporated into the Grand Duchy of Hesse; of the abbey, only the porch remained, adapted as a chapel.
The monumental complex of the conventual buildings suffered various vicissitudes over the centuries. The original church of St. Nazarius, consecrated on 1 September 774 in the presence of Charlemagne, who had been elected king in May of that same year, was destroyed by fire on 21 March 1090. The new church was consecrated in 1130. During the 12th century, many expansion works were carried out, and in the following century the Premonstratensians rebuilt the choir and introduced some restorations that led to a third consecration in 1266. After the siege and fire of 1621, the buildings fell into a state of abandonment, from which only the porch, or Königshalle, survived. This is considered the oldest monument of Frankish religious architecture (though some scholars believe it dates after the fire of 1090; cf. M. R. de Lasteyrie, *Architecture religieuse en France à l'époque romane*, Paris 1912, pp. 167–171). Excavations conducted in 1927–28 revealed a crypt used as a sepulchral chapel (perhaps from 876) containing the tombs of Louis the German, Louis III the Younger, and Cunigunde, wife of Conrad I.
Much of the ancient library of the monastery has also been lost; its precious and substantial collection of books was transferred in the 16th century to the Palatine Library in Heidelberg, and in 1632 Count Ottheinrich ceded what remained of it to the Pope. The surviving manuscripts are now in the Vatican Library, in the Palatine collection: to attest to the former splendor, some old catalogues remain (mss. Vat. Palat. lat. 1877, ff. 1–34, 44–79; Palat. lat. 57, a notebook added at the beginning). The rear leaf of an ivory diptych that once covered an evangelary from Lorsch is now in the Vatican Sacristy (the other leaf is in the Victoria and Albert Museum, London). Not all the monasteries originating from Lorsch can be identified as products of its scriptorium; however, it is proven that it was already very active at the beginning of the 9th century under Abbot Adelung, when a type of pre-Caroline German script was in use, showing evident Merovingian influences alongside traces of insular derivation. The script of Lorsch does not, however, exhibit very distinctive characteristics that would reveal a school direction canonized into fixed forms.